Why is Jumu`ah Prayer Held on Friday?

 Assalamu alaikum wa rahmatullahi wa barakatuh,

I pray that you are well, insha’Allah.

The Friday prayer (salat al-jumu`ah) is held on Fridays due to the explicit Qur’anic command to do so, ‘O ye who believe! When the call is heard for the prayer of the day of congregation, haste unto remembrance of Allah and leave your trading. That is better for you if ye did but know’ [62:9]

The ‘day of congregation’, here, refers to Friday.

The Prohibition of Trading at the time of the Friday Prayer

Imam Abu Bakr al-Jassas mentions, in his commentary of the Mukhtasar al-Tahawi, trade, specifically, is not intended here, rather, anything else which busies one from attending the Friday prayer would also take the same ruling.

Moreover, trading was specifically mentioned here because of the fact that Friday noon was a busy time for traders; so it is as if they are being told, hasten to the trade of the hereafter (akhirah), leave the trading of this world (dunya) and hurry unto the remembrance of God. [Nasafi, Madarik al-Tanzil wa Haqa’iq al-Ta’wil]

The Virtue of Fridays

It is related from the Messenger of God (Allah bless him and give him peace), that he said: “Verily the most virtuous, of your days, is Friday. Send abundant blessings upon me on Fridays because they are presented to me on that day.” [Abu Dawud]

In summary, Fridays are singled out, more emphatically, as days for sending blessings upon the Messenger of God (Allah bless him and give him peace) specifically because the blessings (salawat) are presented to him, accepted. [Abadi, `Awn al-Ma`bud Sharh Sunan Abi Dawud]

And Allah knows best.