Hadith: The Prophet (may Allah's peace and blessings be upon him) ordered us to do seven things and forbade us from doing seven things.

عن البراء بن عازِب رضي الله عنهما قال: «أَمرَنا رسول الله صلى الله عليه وسلم بِسَبْعٍ، وَنَهَانَا عن سَبْعٍ: أَمَرْنَا بِعِيَادَةِ الْمَرِيضِ، وَاتِّبَاعِ الْجِنَازَةِ، وَتَشْمِيتِ الْعَاطِسِ، وَإِبْرَارِ الْقَسَمِ (أَوْ الْمُقْسِمِ)، وَنَصْرِ الْمَظْلُوم، وَإِجابة الدَّاعي، وَإِفْشاءِ السَّلامِ. وَنَهَانَا عن خَوَاتِيمَ- أَو عن تَخَتُّمٍ- بِالذَّهَب، وَعَنْ الشُّرب بِالْفِضَّة، وعن المَيَاثِر، وعن الْقَسِّيِّ، وَعن لُبْسِ الحرِيرِ، وَالإِسْتَبْرَقِ، وَالدِّيباج».
[صحيح] - [متفق عليه]

Al-Barā ibn ‘Āzib (may Allah be pleased with him) reported: The Prophet (may Allah's peace and blessings be upon him) ordered us to do seven things and forbade us from doing seven things. He ordered us to visit the sick, to follow the funeral procession, to invoke Allah's mercy upon someone who sneezes, to help others fulfill their oaths, to help the oppressed, to accept the invitation of others, and to spread the greeting of peace. He forbade us to wear gold rings; to drink in silver utensils; to use Mayāthir (cushions of silk stuffed with cotton and placed under the rider on the saddle) and the Qasiyy (linen clothes containing silk brought from an Egyptian town); and to wear silk, brocade and Dībāj (another fine kind of silk).
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

The Prophet (may Allah's peace and blessings be upon him) was sent in order to perfect good manners. Therefore, he encouraged the Muslims to observe all noble manners and deeds and forbade them to do ugly things. Among the things which he commanded the Muslims to observe is visiting the sick people. It is a duty on the Muslims to visit sick fellow Muslims, to fulfill the right of a Muslim brother, soothe him, and supplicate Allah for him. Also, Muslims should follow the funerals of the dead among them, since this act involves reward for the follower, supplication for the one being followed, greeting the grave dwellers, as well as deriving lessons and admonition. Also, when someone sneezes and praises Allah, one should respond with: "May Allah have mercy upon you." If someone swears that another does something, one should comply and respond to his request so as to save him the expiation of his oath. One is required, as well, to support the oppressed, for doing this features an aspect of averting injustice, repelling the transgressor, preventing his evil, and forbidding what is wrong. Likewise, one should answer the invitation, so as to foster closeness between the hearts and remove negative feelings, for declining the invitation brings about alienation and aversion. If one is called to attend a wedding party, it is obligatory to respond. One should also spread the greeting of peace, for this is a prophetic practice which involves supplication for the Muslims and a cause of amiability. On the other hand, there are also things that are forbidden to do, such as wearing gold rings by men, which is a sign of effeminacy and softness and contradicts manliness. Also, it is forbidden to drink in silver utensils, for it involves extravagance and arrogance. Since drinking in silver utensils is forbidden although it might be needed, other uses are forbidden with greater reason. The Prophet (may Allah's peace and blessings be upon him) mentioned types of silk (Mayāthir, Qasiyy, Dībāj, Istabraq) as forbidden for men, for such clothes lead to comfort and luxury, which are reasons for idleness and laziness. Men should be active, strong, and youthful in order for them to be ready to do their duty of defending their religion, honor, and countries.