Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Nails in a dream are a man's weapon, his strength, and his victory over his enemies. Their length indicates strength and abundance in sustenance. Trimming them indicates following the Sunnah.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Nails indicate wealth. Whoever sees his nails fall off, his wealth is gone.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Nails are interpreted as benefit. Their length indicates an increase in wealth.