Or HaChaim on Exodus 18:6/אור החיים על שמות י״ח:ו׳

1 אני חתנך…ואשתך ושני בניה, "I, your father-in-law as well as your wife and her two sons, etc." Why did the Torah change the order in which Moses' wife and children are mentioned from the order in which they were mentioned in verse five? In verse five the sons are described as belonging to Moses and are mentioned first, whereas here Tzipporah is mentioned first and the sons are described as being hers! Mechilta on our verse explains that Yitro sent word to Moses that if he would not come out to meet him because he was his father-in-law, at least he should come out to meet and to welcome his wife and children. We may therefore assume that the Torah used the same approach in once mentioning Tzipporah before the children and once after the children. If Moses would not come out to welcome Tzipporah as his wife, at least he should welcome her as the mother of his children. When the arrival of these persons in the desert is mentioned, however, they are mentioned in order of their respective importance. This is why the sons are mentioned ahead of Tzipporah. Even though in this instance Yitro mentioned the fact that he was Moses' father-in-law before mentioning his own name, whereas in verse five his name is mentioned before his status as Moses' father-in-law, in verse five the Torah speaks objectively, whereas in our verse the Torah quotes Yitro. Seeing that Yitro was a modest individual he would not mention his name first. Moses would go out to honour Yitro because he was his father-in-law even if he had no other claim to honour. You will find something similar in Samuel I 24,11 where David honoured Saul even though the latter tried to kill him.

2ושני בניה עמה, and her two sons with her. The reason the Torah wrote the word עמה, with her, is to continue the trend of thought mentioned earlier. Yitro said: "if you do not come out on account of her or your children, at least come out to meet her and the children together."