Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Sewing in a dream indicates righteousness of affairs, family reunification, and familiarity. Whoever sees himself sew a garment for himself is reforming his worldly affairs. Whoever sees himself sew people's clothes is advising them.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Sewing indicates repentance and returning to God. For the poor, it is wealth, and for the worried, relief.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Sewing is interpreted as reconciliation. Whoever sees himself sew two garments together is reconciling two men.