John Calvin on 2 Peter 1:18

18. In the holy mount. He calls it the holy mount, for the same reason that the ground was called holy where God appeared to Moses. For wherever the Lord comes, as he is the fountain of all holiness, he makes holy all things by the odor of his presence. And by this mode of speaking we are taught, not only to receive God reverently wherever he shews himself, but also to prepare ourselves for holiness, as soon as he comes nigh us, as it was commanded the people when the law was proclaimed on Mount Sinai. And it is a general truth,

“Be ye holy, for I am holy, who dwell in the midst of you.” (Leviticus 11:44; 19:2.)

2 Peter 1:19-21

19. We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts:

19. Et habemus firmiorem propheticum sermonem, cui bene facitis attendentes, tanquam lucernae apparenti in caliginoso loco, donee illuceat dies, et lucifer oriatur in cordibus vestris;

20. Knowing this first, that no prophecy of the scripture is of any private interpretation.

20. Hoc primùm cognito, quòd omnis prophetia scripturae privatae (vel, proprii motus) interpretationis non est:

21. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.

21. Neque enim voluntate hominis allata est quondam prophetia; sed à Spiritu Sancto impulsi, loquuti sunt sancti Dei homines.