יֵ֭לְכוּ מֵחַ֣יִל אֶל־חָ֑יִל יֵרָאֶ֖ה אֶל־אֱלֹהִ֣ים בְּצִיּֽוֹן׃
They go from strength to strength, every one of them appeareth before God in Zion.
Kitzur Shulchan Arukh
People who are meticulous in observing the mitzvos begin to build the sukkah, immediately after the end of Yom Kippur, fulfilling the verse, "They go from strength to strength" (Psalms 84:8).