Why did Jesus tell a grief stricken mother “Do not weep”?
Her son had died and this true circumstance of his funeral procession going out of the gate of the city is told.  Jesus is coming into the city with His twelve disciples and a large crowd was accompanying Him.  The two crowds meet, and Jesus saw the widow and He felt compassion for her.
(Luke 7:11-13)

Some people are very uncomfortable when others are crying or weeping.  They try to put on a band-aid of pity or sympathy for another’s deep sorrow.

Jesus went to the source of the widow’s grief for her son…and He did not use a band-aid.
He brought healing to her by giving life to her dead son.
Compassion does that, it offers life and not pity; compassion acts in the interest of another.

(NASB) Luke 7:14-15 “And He came up and touched the coffin; and the bearers came to a halt.  And He said, ‘Young man, I say to you, arise!’
15 The dead man sat up and began to speak.  And Jesus gave him back to his mother.”

Where in your life has Jesus given you healing by means of working through another’s life?
Perhaps He has turned around a child (no matter their age), and it has healed the hurt and anguish which parents experience.
Perhaps another’s prayers for you have brought you emotional healing, physical healing, spiritual healing, mental healing…even social healing.

Jesus knew what He was going to do to turn the widow’s grief into joy.  “Do not weep” was not a band-aid of sympathy; rather it was the words of assured power to perform the impossible…to resurrect her dead son.

Only Jesus could have done that work of resurrection.  Only Jesus can turn your tears of sorrow into joy.  Then the living God should be given the glory, the One Who is the Giver of Life.

For what reason do you cry?  Is it from true, heart-felt sorrow?  Jesus said, “Do not weep” to a grieving mother.
Jesus may be saying to you, “Do not weep” for He knows what He is going to do in your life.