The stipulations set in contracts and agreements.
24 · Hadith
Narrated Abu Huraira:Allah's Messenger (ﷺ) mentioned a person who asked an Israeli man to lend him one-thousand Dinars, and the Israeli lent him the sum for a certain fixed period
Narrated `Amra:Aisha said that Barirah came to seek her help in the writing of her emancipation. `Aisha said to her, "If you wish, I will pay your masters (your price) and the wala' will be for me." When Allah's Messenger (ﷺ) came, she told him about it. The Prophet (ﷺ) said to her, "Buy her (i.e. Barirah) and manumit (free) her, for the Wala is for the one who manumits." Then Allah's Messenger (ﷺ) ascended the pulpit and said, "What about those people who stipulate conditions which are not in Allah's Laws? Whoever stipulates such conditions as are not in Allah's Laws, then those conditions are invalid even if he stipulated a hundred such conditions
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "Allah has ninety-nine names, i.e. one-hundred minus one, and whoever knows them will go to Paradise." (Please see Hadith No. 419 Vol)
Narrated Ibn `Umar:Umar bin Al-Khattab got some land in Khaibar and he went to the Prophet (ﷺ) to consult him about it saying, "O Allah's Messenger (ﷺ) I got some land in Khaibar better than which I have never had, what do you suggest that I do with it?" The Prophet (ﷺ) said, "If you like you can give the land as endowment and give its fruits in charity." So `Umar gave it in charity as an endowment on the condition that it would not be sold nor given to anybody as a present and not to be inherited, but its yield would be given in charity to the poor people, to the Kith and kin, for freeing slaves, for Allah's Cause, to the travelers and guests; and that there would be no harm if the guardian of the endowment ate from it according to his need with good intention, and fed others without storing it for the future