A 'Prophet' Calling Himself 'Lord'

S 3:79-80 It was not for a human being that Allah should give him the Book and the wisdom and the prophethood then he says to people: Be slaves to me instead of Allah but: Be rabbaniyun because you have been teaching the Book and because you have been studying. / And he does not command you to take the angels and the prophets as lords. Would he command you to kufr after when you are Muslims?

But:

S 39:53 Say: My slaves who have been extravagant against themselves, do not despair of Allah’s mercy. Allah forgives all sins. He is the forgiver, the merciful.

Allah's boss, supposedly a prophet, has himself telling himself to say to people: MY slaves. Allah is supposedly directing him to say that. If Allah were directing him to say that, how many lords might the Muslims have?

Narrated Jundab bin `Abdullah:

Gabriel did not come to the Prophet (for some time) and so one of the Quraish women said, "His Satan has deserted him." So came the Divine Revelation: "By the forenoon And by the night When it is still! Your Lord (O Muhammad) has neither Forsaken you Nor hated you." (93.1-3)

https://sunnah.com/bukhari/19/5

Chronologically, S 39 comes before S 3.

We might add S 9:31

They have taken their rabbis and their monks as lords instead of Allah and the Messiah the son of Maryam. And they were not commanded but to worship one god. There is no god but him. Praise be to him from what they associate!

Going by the natural reading of this verse, Allah and the Messiah, supposedly just a prophet, are to be taken as lords.

Noun

رَبّ • (rabb) m (plural أَرْبَاب‎ (ʔarbāb) or رُبُوب‎ (rubūb), feminine رَبَّة‎ (rabba))

1. verbal noun of رَبَّ (rabba) (form I)

2. master, lord, king, sovereign, potentate coordinate terms ▲quotations ▼Coordinate terms: عَبْد‎ (ʕabd), خَادِم‎ (ḵādim)‏رَبُّ الدَّار‎ ― rabbu d-dār ― master of the house‏رَبُّ الْعَائِلَة‎ ― rabbu l-ʕāʔila ― paterfamilias

3. Lord, an epithet of God‏اَللهُ رَبُّ الْعَالَمِين‎ ― allāhu rabbu l-ʕālamīn ― God is Lord of the Worlds‏الرَّبّ‎ ― ar-rabb ― the LORD

4. god, deity quotations ▼

5. leader, chief, head‏رَبُّ بَحْرِيّ‎ ― rabbu baḥriyy ― seaman (naval rank)

6. owner, proprietor

7. (with a following genitive) one possessed of, one endowed with

8. (with a following genitive) having to do with رب - Wiktionary

Further reading:

Chronological Order of the Qur'an - WikiIslam

Another Stray Say: Are Muslims the Slaves of Muhammad?

The Quran’s many Gods and Lords: An Analysis of the Worship given to And Deification of Creatures within the Islamic Text