Until worldly goods come between you, you are brothers

Ahmad ibn Ammar al-Asdi (may Allah have mercy on him) said:

“Once we, together with our teacher, accompanied by his students, went out to read janaza-namaz. On the way, the teacher saw dogs that had strayed into a flock, they played among themselves, somersaulted and licked each other.

The teacher turned to the students and said, “Look at these dogs, how well they treat each other.”

Then, on the way back, when we were returning from Janaza, someone threw the corpse of some animal to those dogs, and they pounced on it, and began to squabble among themselves, biting each other and barking. The dogs started a desperate fight over this corpse.

The teacher turned to the students again and said:

“My friends, until worldly goods come between you, you are brothers, but when worldly goods come between you, you will begin to squabble for them, just as these dogs squabble over a corpse.”

See Hafiz ibn Asakir, Tarikh ad-Dimashq 5/85