1. If the letter Lam – ل is always recited lightly, without emphasis:
Except when the letter lam – ل is before the name of Majesty of Allah – اللَّه.
بِسْمِ اللَّهِ الرَّحْمَـٰنِ الرَّحِيمِ
In the name of Allah, the Entirely Merciful, the Especially Merciful. (1:1)
2. If the letter lam – ل is preceded by a letter carrying a fatha or a damma:
It will be recited with emphasis – tafkheem.
Examples: with a fatha:
قُلْ هُوَ اللَّهُ أَحَدٌ
Say, “He is Allah, [who is] One, (112:1)
with a damma:
إِذَا جَاءَ نَصْرُ اللَّهِ وَالْفَتْحُ
When the victory of Allah has come and the conquest, (110:1)