Praise be to Allah.
It says in the hadeeth narrated by ‘Abd al-Razzaaq in his Musannaf from Layth from Taawoos that the Messenger of Allaah SAWS (peace and blessings of Allaah be upon him) said: “… there is no travel by wandering ascetics, no hermitage and no monasticism in Islam.” Al-Albaani said in Da’eef al-Jaami’, “(It is) da’eef.” (no. 6287)
What is saheeh is that which was narrated by Abu Dawood in his Sunan from the hadeeth of Abu Umaamah, that the Prophet SAWS (peace and blessings of Allaah be upon him) said: “The siyaahah (travel of wandering ascetics) of my ummah is jihaad for the sake of Allaah.”
(Classed as saheeh in Saheeh al-Jaami’, no. 2093)
The word saa’ihaat (translated as “emigrants”) in the aayah:
“Muslims (who submit to Allaah), believers, obedient (to Allaah), turning to Allaah in repentance, worshipping Allaah sincerely, given to fasting or emigrants [saa’ihaat] (for Allaah’s sake), previously married and virgins”
[al-Tahreem 66:5 – interpretation of the meaning]
may also mean women who fast, because the word siyaahah has two meanings in the shar’i texts: it may mean jihad or it may mean fasting.
And Allaah knows best.