Revelation 2:7

He that hath an ear--This clause precedes the promise in the first three addresses, succeeds it in the last four. Thus the promises are enclosed on both sides with the precept urging the deepest attention as to the most momentous truths. Every man "hath an ear" naturally, but he alone will be able to hear spiritually to whom God has given "the hearing ear"; whose "ear God hath wakened" and "opened." Compare "Faith, the ears of the soul" [CLEMENT OF ALEXANDRIA]. the Spirit saith--What Christ saith, the Spirit saith; so one are the Second and Third Persons. unto the churches--not merely to the particular, but to the universal Church. overcometh--In John's Gospel (Joh 16:33) and First Epistle (Jo1 2:13-14; Jo1 5:4-5) an object follows, namely, "the world," "the wicked one." Here, where the final issue is spoken of, the conqueror is named absolutely. Paul uses a similar image (Co1 9:24-25; Ti2 2:5; but not the same as John's phrase, except Rom 12:21). will I give--as the Judge. The tree of life in Paradise, lost by the fall, is restored by the Redeemer. Allusions to it occur in Pro 3:18; Pro 11:30; Pro 13:12; Pro 15:4, and prophetically, Rev 22:2, Rev 22:14; Eze 47:12; compare Joh 6:51. It is interesting to note how closely these introductory addresses are linked to the body of Revelation.

— Jamieson-Fausset-Brown Commentary (public domain)