Sulayman bin al-Mughirah says: In the Battle of Uhud the Ansar suffered wounds and also had to endure hardship. The Ansar told this to the beloved Prophet (peace and blessings be upon him) and said: What do you command us? He (peace and blessings be upon him) said: "Make the graves wide." Abdullah says: I think he (peace and blessings be upon him) said: "Make them deep." Then Abdullah said: Rather, it was exactly like that.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6752