وَ اِذَا حُیِّیْتُمْ بِتَحِیَّةٍ فَحَیُّوْا بِاَحْسَنَ مِنْهَاۤ اَوْ رُدُّوْهَاؕ-

And when someone greets you with some words (of greeting), respond therefore with words better than that or return the same;

[Kanz-ul-Iman (translation of Quran)] (Part 5, Surah An-Nisa, verse 86)

Best method of replying to Salam

Imam-e-Ahl-e-Sunnat, Mujaddid of the Ummah, Maulana Shah Imam Ahmad Raza Khan رَحْمَةُ الـلّٰـهِ عَـلَيْه has stated on page 409 of Fatawa Razawiyyah, volume 22: One should at least say the words اَلسَّلَامُ عَلَیْکُمْ; it is better to add وَ رَحْمَۃُ اللّٰہِ and it would be best to add وَبَرَکَاتُہٗ, but nothing more. The one replying must say at least the same words however, it is better to add the aforementioned words. For example, if one is greeted with اَلسَّلَامُ عَلَیْکُمْ then one should reply with وَ عَلَیْکُمُ السَّلَامُ وَ رَحْمَۃُ اللّٰہ. If he is greeted with    اَلسَّلَامُ عَلَیْکُمْ وَ رَحْمَۃُ اللّٰہ, then one should reply وَ عَلَیْکُمُ السَّلَامُ وَ رَحْمَۃُ اللّٰہِ وَبَرَکَاتُہٗ. If one is greeted with اَلسَّلَامُ عَلَیْکُمْ وَ رَحْمَۃُ اللّٰہِ وَبَرَکَاتُہٗ, then one should reply with the same words, and nothing more.

صَلُّوۡا عَلَى الۡحَبِيۡب                                                                 صَلَّى اللّٰهُ عَلٰى مُحَمَّد

Satan was the first to be envious

Dear Islamic brothers! We ought to act upon the statement of the Beloved Prophet صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم and keep our hearts free from envy and malice by being the first to give Salam to those younger than us and those older. If ever feel jealousy in our hearts towards any Muslim, then we should repent at once, fearing the punishment of Allah Almighty. Let it not be that Allah Almighty becomes displeased with us due to this satanic act and we might destroy our worldly life and the life of the Hereafter. Remember! Jealousy was the first sin committed in the heavens, which was committed by Satan. Imam Jalaluddin Suyuti