heart = (qalb) قَلْب

Plural: قُلُوب
Associated verb: to invert, turn s. upside-down قَلَب (يَقْلِب) ه – قَلْبًا

Examples

مَا أَصَابَ مِن مُصِيبَةٍ إلا بِإِذْنِ الله وَمَن يُؤْمِن بالله يَهْدِ قَلْبَهُ وَاللهُ بِكُلّ شَيْءٍ عَلِيمٌ No kind of calamity can occur, except by the leave of God: and if any one believes in God, (God) guides his heart (aright): for God knows all things. – Quran, 64:11

عَنْ أَبِي عَبْدِ الله النّعْمَانِ بْنِ بَشِيرٍ قَالَ: سَمِعْتُ رَسُولَ الله صَلّى الله عَلَيْهِ وَسَلّمَ يَقُولُ : … أَلا إِنّ فِي الْجَسَدِ مُضْغَةً إِذا صَلَحَتْ صَلَحَ الْجَسَدُ كُلّهُ ، وَإِذا فَسَدَتْ فَسَدَ الْجَسَدُ كَلّهُ ، أَلا وَ هِيَ الْقَلْبُ On the authority of al-Nu’man b. Bashir, he said I heard the Messenger of God, God bless him and grant him peace, say, “…Truly in the body there is a piece of flesh, if it is sound the entire body is sound, and if it is corrupted, the entire body is corrupted, truly it is the heart.” – al-Bukhari

لِيبِيا : مُوَاجَهاتٌ مُسَلّحَةٌ فِي قَلْبِ الْعَاصِمَةِ طَرابُلُس Libya: armed confrontations in the heart of the capital Tripoli – BBC News, Arabic

Did you know…

As mentioned above, the word قَلْب heart comes from the verb قَلَب to invert, turn upside down, for which the verbal noun is also قَلْب , meaninginverting, turning upside-down. This double-meaning of the word قَلْب was played upon by Shaykh Muhammad Mawlud in the beginning of his poem مَطْهَرَة الْقُلُوب (the Purification of the Hearts), when he says: فَقُلْتُ بَادِئًا بِقَلْبِ الْبَدْءِ إِذْ هُوَ أَشْرَفُ مَعَالِي الْبَدْءِ I begin by starting with the heart of beginnings, for it is the highest and noblest of beginnings (translation by Shaykh Hamza Yusuf). His saying heart of beginnings, given the two aforementioned meanings of the word قَلْب may therefore also be translated inversion of beginning (b-d-a), in other words أَدَب etiquette (adab). So the author is telling us that correct etiquette towards learning is the the heart of beginnings.