Jamieson, Fausset and Brown on Philippians 2:17

17. Yea, and if--rather as Greek, "Yea, if even"; implying that he regarded the contingency as not unlikely: He had assumed the possibility of his being found alive at Christ's coming (for in every age Christ designed Christians to stand in preparedness for His coming as at hand): he here puts a supposition which he regards as more likely, namely, his own death before Christ's coming.

I be offered--rather as Greek, "I am poured out." "I am made a libation." Present, not future, as the danger is threatening him now. As in sacrifices libations of wine were "poured upon" the offerings, so he represents his Philippian converts, offered through faith (or else their faith itself), as the sacrifice, and his blood as the libation "poured upon" it (compare Ro 15:16; 2Ti 4:6).

service--Greek, "priest's ministration"; carrying out the image of a sacrifice.

I joy--for myself (Php 1:21, 23). His expectation of release from prison is much fainter, than in the Epistles to Ephesians, Colossians, and Philemon, written somewhat earlier from Rome. The appointment of Tigellinus to be Prætorian Prefect was probably the cause of this change. See Introduction.

rejoice with you all--Alford translates, "I congratulate you all," namely on the honor occurring to you by my blood being poured out on the sacrifice of your faith. If they rejoiced already (as English Version represents), what need of his urging them, "Do ye also joy."