3 Nephi 19

After having taught or ministered the same words Jesus had taught the previous day, His twelve authorized disciples -

"...did pray for that which they most desired; and they desired that the Holy Ghost should be given unto them."  (Book of Mormon | 3 Nephi 19:9)

So they followed the commandments of the Savior and were baptized and -

"...when they were all baptized and had come up out of the water, the Holy Ghost did fall upon them, and they were filled with the Holy Ghost and with fire." (Book of Mormon | 3 Nephi 19:13)

And now having been cleansed by fire and with the Holy Ghost -

"...they were encircled about as if it were by fire; and it came down from heaven, and the multitude did witness it, and did bear record; and angels did come down out of heaven and did minister unto them.
15  And it came to pass that while the angels were ministering unto the disciples, behold, Jesus came and stood in the midst and ministered unto them."  (Book of Mormon | 3 Nephi 19:14 - 15)

I can't help but ponder what the angels and the Savior were doing as they ministered to these disciples.  My thoughts are what has always been done as new priesthood leaders are called...that is, they are taught their duties.
One more thought.  The Savior had previously instructed these disciple to -

"...ye must always pray unto the Father in my name..."  (Book of Mormon | 3 Nephi 18:19)

Yet we read that upon the Savior's return, the disciples -

"...began to pray; and they did pray unto Jesus, calling him their Lord and their God."  (Book of Mormon | 3 Nephi 19:18)

I have wondered if in this case that Mormon used the word pray to reflect righteous praise and worship.  But even so, the Savior provides a solid reason as He went a little way off and prayed -

"Father, thou hast given them the Holy Ghost because they believe in me; and thou seest that they believe in me because thou hearest them, and they pray unto me; and they pray unto me because I am with them."  (Book of Mormon | 3 Nephi 19:22)

Again, my reasoning could be right in that they were speaking directly to Jesus.