Paul cannot understand how people who have come to know God would choose to go back into slavery. They had been freed from serving false gods. Now they were taking up the observance of "days, and months, and times, and years" (Galatians 4:10). Barnes says the absurdity "is as great as it would be for a man who had been freed from slavery to desire his chains again."

Paul also corrects himself mid-sentence: "or rather are known of God." Barnes explains that he did this to avoid the impression "that their acquaintance with God was owing to themselves." The question presses them with this: God took the first step toward you; why would you walk back into chains?

The Galatians' answer is not recorded. Paul goes on to name what they were doing: "Ye observe days, and months, and times, and years" (Galatians 4:10). He admits his fear: "I am afraid of you, lest I have bestowed upon you labour in vain" (Galatians 4:11). Then he pleads with them, "Brethren, I beseech you, be as I am" (Galatians 4:12), and later urges, "be not entangled again with the yoke of bondage" (Galatians 5:1).

Most of the Galatian believers had been Gentiles who served idols (Galatians 4:8), so how could they turn "again" to Jewish rites they had never kept? Gill answers that there was some likeness between the pagan ceremonies they had left and the Jewish observances they were now taking up; either way, it was bondage. "Elements" is the Greek stoicheia, which Thayer defines as first things or rudiments, the basic principles of a subject. Barnes says they are called "weak" because they had "no power to justify the sinner before God," and "beggarly" (Greek ptōcha, poor) "because they could not impart spiritual riches."

The heart of this question is God's initiative. In Greek, "known" appears twice in the verse: first the Galatians "have known God," then, more importantly, they "are known of God." Matthew Henry writes, "All our knowledge of God begins on his part; we know him because we are known of him." Gill says what knowledge they have, "they have it first, originally, and wholly from him."

That is why turning back is so serious. God had adopted them as sons and given them "the Spirit of his Son" crying "Abba, Father" (Galatians 4:6). Going back to rituals to win God's favor treats sons as if they were still slaves. Paul's question calls them to live as the free children God has already made them.