After the victory of Gaza, the Muslim army headed northwards alongside the Mediterranean coast, passing through such great Islamic cities as Ashkelon and then Yafa – we ask Allaah, the Almighty, to liberate them as well as all the Palestinian territories from the filth of the Jews – and it is well-known, my brothers, that Tel Aviv was founded directly North of Yaafa. Qutuz and his army continued their advance northwards and came upon the west part of Tulkarm, then to Haifa and then Acre, the Muslim city that was occupied by the Crusaders.

Qutuz, May Allaah have mercy upon him, camped in the gardens surrounding the Acre fortress, in the valley lying east of Acre. Then, the correspondences between Qutuz, May Allaah have mercy upon him, and the Crusader emirs of Acre began, to confirm once again the previous agreements. Qutuz, May Allaah have mercy upon him, sent a delegate from the Muslim emirs who entered the Acre Fortress and were received kindly by the Crusaders. Both parties confirmed the previous agreements, and there was more than one visit, until both parties felt assured about the stability of the circumstances.

Then, Qutuz, May Allaah have mercy upon him, decided to leave Acre and choose a suitable place for the expected important meeting between him and the Tatars.

When Qutuz, May Allaah have mercy upon him, started to leave Acre, a Muslim emir who had taken part in the embassy to the Crusaders, suggested that since Acre was now in its weakest state, and the Crusader emirs were assured about the Islamic treaty, and unprepared to fight, then, should Qutuz turn against them, he might probably be able to overthrow the Acre Fortress and liberate the Islamic city from the Crusader occupation that had started one hundred and sixty-six years earlier. However, Qutuz, May Allaah have mercy upon him, gave his decisive, strict and clear reply, saying: "We never betray treaties."
O Allaah! The vision is clear-cut in the eyes of Qutuz, May Allaah have mercy upon him.

That is leadership which utilizes the real means of victory; and among those means is to follow the Conditions of Allaah, the Almighty in every matter, be it significant or insignificant; and keeping the contracts, and not repealing the covenants that are from the very Laws of Allaah the Almighty. In confirmation of that, Allaah the Almighty Says (what means): {O you who have believed, fulfill [all] contracts.} [Quran 5:1]

Here, I would like to relate to the Jews, the Crusaders, the Tatars, and all the world, the Hadeeth of the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, narrated by both Abu Daawood and At-Tirmithi, who renders it as Hasan Saheeh, on the authority of ‘Amr ibn ‘Abasah, May Allaah be pleased with him. He narrated that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: "Let the one, between whom and people there is a covenant, neither break nor change it whatsoever, until it terminates, otherwise, let him throw [their covenant] back to them, [putting himself] on equal terms."
You have only two ways: either to wait until the covenant terminates, or tell your enemies that you are going to break it for some reason. However, there is no place for treachery in the Islamic covenants.

That is indeed the religion of Islam, and that is the Sharee‘ah of Islam, and those are the laws of Islam, and those are the leaders of Islam.
Qutuz, May Allaah have mercy upon him, left Acre and headed South-East in search of a suitable place for the next battle. At the same time, the remaining troops of the Tatar army who had fled from Gaza reached Kitbuqa and told him about the movements of the Muslim army. Kitbuqa grew very angry because of the defeat of his garrison in Gaza, and was enraged even more because there were Muslims gathering to fight him, as if the Muslims, in principle, had no right of resistance; and if they resisted their enemy, this should infuriate Kitbuqa and the Tatars. Kitbuqa then held an advisory meeting with his leaders, and this meeting was attended by Al-Ashraf Al-Ayyoobi of Homs. Kitbuqa made his decision in this meeting to move quickly to fight the Muslim extremists who would spoil the peace process between Kitbuqa and the Muslim leaders, and put the Tatar-Islamic negotiations at risk.

It was clear that the movement of the Tatars towards the Muslims was so slow that it enabled Qutuz to cut most of Palestinian coast from South to North before the Tatars could enter the Palestinian borders, despite the fact that the distance between the Biqaa‘Valley of Lebanon and the Lebanese-Palestinian borders was no more than 100 kilometers, and it would take 2-3 days for the army to cover that distance. The point is that Qutuz, May Allaah have mercy upon him, was the first to move in search for a suitable place for the battle. That was a good point in his favor, which enabled him to arrange the brigades of his army in a better way tests the region and know well its nature and secret places.

https://www.islamstory.com/en/artical/20777/to-ayn-jaaloot