Romans 16:4

“Who for my life laid down their necks, etc..] That is, exposed themselves to great danger to save the apostle's life: the allusion is to the manner of executions by beheading, and to one person's laying down his head, and offering his neck to the executioner the room of another: this we are not to suppose was literally done; but the design of the expression is, that in some shape or another they risked their own lives for the apostle's; which might be done either at the insurrection in Corinth against Paul, when the Jews dragged him to the judgment seat of Gallio, and beat Sosthenes the ruler of the synagogue before him; or the uproar in Ephesus by Demetrius and the craftsmen, when Paul and…”

“who have for my life laid down--"who did for my life lay down" their own necks--that is, risked their lives; either at Corinth (Act 18:6, Act 18:9-10), or more probably at Ephesus (Act 19:30-31; and compare Co1 15:32). They must have returned from Ephesus (where we last find them in the history of the Acts) to Rome, whence the edict of Claudius had banished them (Act 18:2); and doubtless, if not the principal members of that Christian community, they were at least the most endeared to our apostle. unto whom not only I give thanks, but also all the churches of the Gentiles--whose special apostle this dear couple had rescued from imminent danger.”

“Who have for my life - In order to save my life. Laid down their own necks - To “lay down the neck” is to lay the head on a block to be cut off with the axe; or to bow down the head as when the neck was exposed to be cut off by the sword of the executioner. The meaning is, that they had hazarded their lives, had exposed themselves to imminent danger, to save the life of Paul. On what occasion this was done, is not known, as it is not referred to in the New Testament elsewhere. As Paul, however, lived with them Acts 18:3, and as he was often persecuted by the Jews, it is probable that he refers to some such period when he was persecuted, when Aquila and Priscilla took him into their house at…”

“Who have for my life, as it were, laid down their own necks - That is, exposed themselves to the utmost danger. But likewise all the churches of the gentiles - Even that at Rome, for preserving so valuable a life. Romans 16:5”

“have: Rom 5:7; Joh 15:13; Phi 2:30; Jo1 3:16 laid: Jos 10:24; Sa2 22:41; Mic 2:3 also: Act 15:41, Act 16:5; Co1 7:17, Co1 16:1; Th1 2:14; Rev 1:4 Romans 16:5”