Not to all the people - Not to the nation at large, for this was not necessary in order to establish the truth of his resurrection. He, however, showed himself to many persons. See the Harmony of the Accounts of the Resurrection of Jesus.
Chosen of God - Appointed by God, or set apart by his authority through Jesus Christ.
Who did eat and drink ... - And by doing this he furnished the clearest possible proof that he was truly risen; that they were not deceived by an illusion of the imagination or by a phantom. Compare John 21:12-13.