Talmud zu Schemuel II 15:30

¹For a full discussion of what is prohibited to a mourner, cf. M.Ḳ. 15a, b and 21a, b (Sonc. ed., pp. 90ff, 133ff). The law is based on Ezek. 24, 17, 23 where the prophet is warned not to observe the usual rites of mourning. A mourner is forbidden to read the Pentateuch, Prophets and Hagiographa;²Because the study of the Torah is a joy. he is also forbidden to study Mishnah, Talmud, halakoth and ’aggadoth. He is under the prohibition to bathe, anoint [the body], put on sandals³These and covering the head are signs of mourning; cf. 2 Sam. 15, 30, Jer. 14, 3f, Esth. 6, 12. and cohabit. He is obliged to cover his head and overturn his couch.⁴Cf. M.Ḳ. 15a, b (Sonc. ed., p. 92): God says, ‘I have set the likeness of Mine image on them and through their sins have I upset it; let your couches be overturned on account thereof’. According to A. Marmorstein the rite served the purpose of warning the mourners against sexual intercourse which is forbidden in the days of mourning; cf. j.Ber. III, 1, 6a.
It is related of Rabban Gamaliel⁵Cf. Ber. 16b (Sonc. ed., p. 96). that when his wife died he bathed on the first night. His disciples said to him, ‘Master, have you not taught us that a mourner is forbidden to bathe?’ He replied, ‘I am not like other men, I am delicate’.