Jamieson, Fausset and Brown on Philippians 1:26

26. Translate, "That your matter of glorying (or rejoicing) may abound in Christ Jesus in me (that is, in my case; in respect to me, or for me who have been granted to your prayers, Php 1:19) through my presence again among you." Alford makes the "matter of glorying," the possession of the Gospel, received from Paul, which would abound, be assured and increased, by his presence among them; thus, "in me," implies that Paul is the worker of the material of abounding in Christ Jesus. But "my rejoicing over you" (Php 2:16), answers plainly to "your rejoicing in respect to me" here.