It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: "Curse is upon men who imitate women and upon women who imitate men, and upon secluded men who say that they will not marry, and upon secluded women who say the same, and upon the one who travels alone in the wilderness." This matter affected the companions (may Allah be pleased with them) so much that its effects became visible on their faces, and the Noble Prophet (peace and blessings be upon him) also mentioned the one who spends the night alone.