Prophets are called as عليه السلام and Sahaba are called as رضي الله عنه. What is the logic behind it?

Question

Prophets are called as عليه السلام and sahabas are called as رضي الله عنه. What is the logic behind it? And if we called sahaba as عليه السلام, is it forbidden in Islam and if it is forbidden why it is so?

Answer 1

This is proper adab that is taught by Quran.

For Muhammad:

إِنَّ اللَّـهَ وَمَلَائِكَتَهُ يُصَلُّونَ عَلَى النَّبِيِّ يَا أَيُّهَا الَّذِينَ آمَنُوا صَلُّوا عَلَيْهِ وَسَلِّمُوا تَسْلِيمًا 33:56

For Prophets and Angels:

37:181 وَسَلَامٌ عَلَى الْمُرْسَلِينَ

For Sahaba:

وَالسّـٰبِقونَ الأَوَّلونَ مِنَ المُهـٰجِرينَ وَالأَنصارِ وَالَّذينَ اتَّبَعوهُم بِإِحسـٰنٍ رَضِىَ اللَّـهُ عَنهُم 9:100

Answer 2

عليه السلام and رضي الله عنه are the pray (good wish) for Prophets and Sahaba. Maybe calling عليه السلام for a Sahaba or . رضي الله عنه. for a Prophet is not haraam but may cause misunderstandings.