This is a polite way to talk about someone dying. AT: "will not die" or "will not end" (See: [[rc://en/ta/man/translate/figs-euphemism]])
# until all of these things
The phrase "these things" refers to the days of tribulation.
# Heaven and earth
The two extremes are given to refer to all of the sky, including the sun, moon, stars, and planets, and all of the earth. AT: "The sky, the earth, and everything in them" (See: [[rc://en/ta/man/translate/figs-merism]])
# will pass away
"will cease to exist." Here this phrase refers to the world ending.
# my words will never pass away
Jesus speaks of words not losing their power as if they were something that will never physically die. AT: "my words will never lose their power" (See: [[rc://en/ta/man/translate/figs-metaphor]])
# that day or that hour
This refers to the time that the Son of Man will return. AT: "that day or that hour that the Son of Man will return" or "the day or the hour that I will return" (See: [[rc://en/ta/man/translate/figs-explicit]])
These words specify some of those who do not know when the Son of Man will return, different from the Father, who does know. AT: "no one knows—neither the angels in heaven nor the Son know—but the Father" or "neither the angels in heaven nor the Son know; no one knows but the Father" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
It is best to translate "Father" with the same word that your language naturally uses to refer to a human father. Also, this is an ellipsis, stating that the Father knows when the Son will return. AT: "but only the Father knows" (See: [[rc://en/ta/man/translate/figs-ellipsis]])