Jesus uses two questions to introduce what he is about to teach. AT: "I will tell you what the kingdom of God is like ... what I can compare it to." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This is basically the same as the previous question. Some languages can use both questions, and some would use only one. (See: [[rc://en/ta/man/translate/figs-parallelism]])
A mustard seed is a very small seed that grows into a large plant. If this seed is not known, the phrase can be translated with the name of another seed like it or simply as "a small seed." (See: [[rc://en/ta/man/translate/translate-unknown]])
"planted in his garden." People planted some kinds of seeds by throwing them so that they scattered in the garden. (See: [[rc://en/ta/man/translate/figs-explicit]])
The word "big" is an exaggeration that contrasts the tree with the tiny seed. AT: "a very large shrub" (See: [[rc://en/ta/man/translate/figs-hyperbole]])