Tradition of respecting the Imam (atjf) in Ghaybah.
There is a Hadith that the name of Imam al-Hujjah (aj) was mentioned in front of Imam Redha (as). Upon hearing Imam al-Hujjah’s name, Imam Redha (as) stood up and put his hand on his head and arose in respect, praying for the emergence of Imam Zaman (aj).
[Abdul-Husain Ahmad Amini Najafi, Al-Ghadir, vol. 2, pg. 361; Sheikh Abbas Qommi, Muntahal-Amal, fourteenth chapter, chapter six, pg. 1127.]
Imam Sadiq (as) was asked about why when the name of the al-Qa’im is mentioned, all must stand.
The Imam (as) replied,
“The Qaim’s occultation will be prolonged, and this name is a remembrance of his future ruler ship and a way of expressing sorrow for his loneliness. As a result, he takes a caring look at the followers of his who remember him with this name out of the love and affection he has for them. It is respectful for the humble servant to stand before his master (the master of his time) when he (the master) is looking at him. Therefore, he must stand and pray for the return of his master.“
[Lotfollah Safi Golpaygani, Muntakhabul-Athar, pg. 506]
This is also an expression of,
"I’m at your service and ready for your command.”