(Allah has sent down the Best Statement, a Book, its parts resembling each other (and) oft-repeated. The skins of those who fear their Lord shiver from it. Then their skin and their heart soften to the remembrance of Allah) (39:23). He connect that with mention of the doomed, those who turn away from the Qur'an and do not benefit from hearing the Words of Allah. Instead, they turn to listening to flutes and singing accompanied by musical instruments. As Ibn Mas`ud commented about the Ayah:
The words: يُؤْتُونَ الزَّكَاةَ (pay Zakah) in Verse 4 carry the injunction of Zakah, although the verse is Makki. This tells us that the original injunction of Zakah had already been revealed before Hijrah, right there in Makkah al-Mu` azzamah. As for the popular assumption that the injunction of Zakah was enforced in the second year of Hijrah, it refers to the arrangement of fixing its nisab (threshold), providing details of obligatory amount to be paid, collecting and disbursing it on authorized heads by the Islamic government. This was done in the second year of Hijrah.
Ibn Kathir while commenting on verse 20 of Surah Al-Muzzammil: وَأَقِيمُوا الصَّلَاةَ وَآتُوا الزَّكَاةَ (Establish Salah and pay Zakah - 73:20) has arrived at the same conclusion, because Surah Al-Muzzammil as one of the Makki surahs was revealed during the very initial period of the revelation of the Qur'an. This tells us that the way Salah and Zakah have been described mostly side by side in the verses of the Qur'an, its obligation had also taken effect side by side. Allah knows best.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.