Charles Spurgeon Commentary Acts 3:1

"Now Peter and John were going up into the temple at the hour of prayer, [being] the ninth [hour]." — Acts 3:1 (ASV)

Peter and John seem to have been linked in closest friendship.

Peter had been brought back by John when he was almost despairing after having denied his Master. John lovingly sought him out and made him his associate; and now they went up together into the temple at the hour of prayer.

Observe, here, how very sweetly the Old Testament dispensation melts into the new. The Temple was no longer what it had been before; the type was of no further use now that the great Antitype of the Temple had come; yet these apostles still went up to it at the hour of prayer.

There are some people who are great at destroying. It will be time to destroy the old when the new is quite ready; and even then, it may be very possible to let the darkness gradually melt away into a twilight, and so the day shall come with no great gap, no marked surprise. So Peter and John went up to the Temple at the same hour as others went. It is folly to be singular, except when to be singular is to be something more right than others.