Seeing a fingernail in a dream signifies victory over an enemy.
Seeing one's nail grow long signifies abandoning the noble Sunnah, because failing to trim the nails at the proper time and allowing them to grow is contrary to the Sunnah, and the source says this does not befit a Muslim.
Seeing nails also signifies strength and power for the dreamer. Thus, seeing one's nail grow so long that it is about to break signifies an increase in strength and wealth.
Ja'far al-Sadiq said that seeing nails is interpreted in four ways: victory over an enemy, adornment and value, wealth, and obtaining something. Cutting one's nails signifies following the noble Sunnah and cleanliness in religion.
Seeing beautiful nails signifies wealth, clothing, weapons with which to resist an enemy, and preparing proof and an answer with which to defend oneself against an opponent.
Seeing one's nail as white as snow signifies memory and understanding.
Seeing the nails in their normal condition signifies well-being in religion and worldly affairs.
Seeing one's nails completely absent signifies bankruptcy and the loss of power and strength.
Ibn Kathir said that seeing nails is interpreted in six ways: strength, measure, courage, an intelligent child, benefit, and a servant.
Seeing the nails deficient or shortened signifies loss of wealth and weakness in power and strength; seeing a nail torn off or broken has the same meaning. Cutting one's nails is interpreted as giving the alms of fitr. If a person at war sees his nail like the talon of a bird of prey, it signifies victory over the enemy.
Seeing one's nail longer than the enemy's nail signifies subduing and defeating the enemy.