Is it obligatory to offer salaam to every acquaintance, even if the acquaintance is superficial and formal? Is there a sin incurred by not offering salaam to female classmates with whom there is no strong relationship? Is it considered forbidden to refrain from offering salaam to a girl who harbors hatred and intentionally causes annoyance, especially given efforts to avoid her?

Initiating a greeting (salam) is a Sunnah according to the majority of scholars, though some deem it obligatory. It is the greeting of the people of Paradise and the key to affection and harmony among Muslims, and a cause for entering Paradise and receiving forgiveness. A Muslim should spread greetings to those they know and those they do not know, while being keen on shaking hands due to the forgiveness of sins it entails. As for avoiding someone from whom harm is feared, there is no sin in it; rather, boycotting may be legislated if the situation necessitates it to protect one's religion or worldly affairs.