Surat Ibrahim (25-26)

{تُؤْتِي أُكُلَهَا كُلَّ حِينٍ بِإِذْنِ رَبِّهَا وَيَضْرِبُ اللّهُ الأَمْثَالَ لِلنَّاسِ لَعَلَّهُمْ يَتَذَكَّرُونَ} (إبراهيم : 25)

25- It gives its abundant and good fruits in a fixed time by the will of its Creator.

These examples which Allah sets from peoples' lives to increase their understanding, observe, compare, remember, ponder over, and take a lesson.

A believer is like a good tree who pronounces the highest and sublime phrase in the existence which is the phrase of monotheism "La Ilaha Illa Allah." This phrase brings its good fruit when a person pronounces it sincerely from the bottom of his heart then confirms it with righteous deeds such as calling to Allah, fighting in the cause of Allah, and spreading goodness. A good tree is the palm tree according to most views.

{وَمَثلُ كَلِمَةٍ خَبِيثَةٍ كَشَجَرَةٍ خَبِيثَةٍ اجْتُثَّتْ مِن فَوْقِ الأَرْضِ مَا لَهَا مِن قَرَارٍ} (إبراهيم : 26)

26- The similitude of a bad word such as disbelieving in Allah or falsehood in general is like a bad tree that has a bad smell, taste, image …etc. You see the bad tree apparent and high on the ground, but its roots are light and not deep. So, when you cut such a tree, it seems like it has no roots, likewise disbelief and polytheism which have no proof, firmness, or power, but they contain deviation, error, and unhidden harms.