"There were about 2500 persons who saw and felt his physical body on that occasion (see 3 Nephi 17:25). Even at three or four seconds each, 'one by one,' that would take several hours. The passage we have just read is one of the greatest scriptural records in our possession. It is clear that 'showing' himself involved more than having them merely look. It was sight, sound, touch, and a witness of the Spirit." (Book of Mormon Symposium Series, "The Keystone Scripture", edited by PR Cheesman, MS Nyman, and CD Tate, Jr., 1988, p. 31)
Howard W. Hunter
"That experience took time, but it was important that each individual have the experience, that each set of eyes and each pair of hands have that reaffirming, personal witness. Later Christ treated the Nephite children exactly the same way. 'He took their little children, one by one, and blessed them, and prayed unto the Father for them' (3 Nephi 17:21 emphasis added)." (Teachings of Howard W. Hunter, p. 209)
Jeffrey R. Holland
"At that invitation, the entire multitude went forth 'one by one,' thrusting their hands into his side and feeling the prints of the nails in his hands and feet. Even though the power of the Resurrection could have—and undoubtedly one day will have— completely restored and made new the wounds from the crucifixion, nevertheless Christ chose to retain those wounds for a purpose, including for his appearance in the last days when he will show those marks and reveal that he was wounded 'in the house of [his] friends' (DC 45:52).
"The wounds in his hands, feet, and side are signs that in mortality painful things happen even to the pure and the perfect, signs that tribulation is not evidence that God does not love us. It is a significant and hopeful fact that it is the wounded Christ who comes to our rescue. He who bears the scars of sacrifice, the lesions of love, the emblems of humility and forgiveness is the Captain of our Soul. That evidence of pain in mortality is undoubtedly intended to give courage to others who are also hurt and wounded by life, perhaps even in the house of their friends.
"In spite of the size of the great multitude, Christ nevertheless took time for each one to have that personal experience." (Christ And The New Covenant, p. 259)