He mentions in Para 1, Surah Baqarah, verse 2 and 3:

هُدًى لِّلْمُتَّقِیْنَۙ(۲) الَّذِیْنَ یُؤْمِنُوْنَ بِالْغَیْبِ وَ یُقِیْمُوْنَ الصَّلٰوةَ وَ مِمَّا رَزَقْنٰهُمْ یُنْفِقُوْنَۙ(۳)

 Guidance for those who fear (Allah). Those who believe without seeing, and keep Salah (the five daily prayers) established and spend in Our path from the sustenance We have bestowed (upon them).

[Kanz-ul-Iman (Translation of Quran)] (Part 1, Surah Al-Baqarah, verse no. 2, 3)

صَلُّوۡا عَلَى الۡحَبِيۡب                                                                 صَلَّى اللّٰهُ عَلٰى مُحَمَّد

O devotees of the Holy Prophet! Truly, very fortunate are those Muslims who fulfil the rights of their wealth that are necessary to fulfil.

   ٭Fortunate are those Muslims who wholeheartedly pay complete Zakah and Fitrah on time.

   ٭Who spend their wealth on their parents, siblings and children.

   ٭Who feed the poor and needy people on the occasion of Sawyam, Daswan, Chaleeswan and Barsi, etc. upon the death of their relatives to convey them reward.

   ٭Who distribute the booklets of Maktaba-tul-Madinah to convey reward.

   ٭Who arrange for Langar-e-Razawiyyah (feeding Muslims, giving food at Sahari and Iftari) with good intentions.

   ٭Who spend their wealth sincerely on the gatherings where the Holy Quran is recited, where Na’ts are recited and at Sunnah-inspiring Ijtimas whilst being mindful of the rights of others.

   ٭Who participate in the construction and running of Masajid, Jami’a-tul-Madinah, Madaris-ul-Madinah and other departments of Dawat-e-Islami.

   ٭Who spend their wealth on the students gaining Islamic knowledge.

Through His grace, Allah عَزَّوَجَلَّ grants double, rather even more than double to those who spend money like this sincerely. For the pleasure of Allah عَزَّوَجَلَّ, give your charity to Dawat-e-Islami and persuade others to also do the same.

صَلُّوۡا عَلَى الۡحَبِيۡب                                                                 صَلَّى اللّٰهُ عَلٰى مُحَمَّد

Dear Islamic brothers! The Holy Quran and Ahadees mention many virtues of giving Sadaqah and charity, and spending in the way of Allah عَزَّوَجَلَّ. Spending in the way of Allah عَزَّوَجَلَّ is also very beneficial for a person himself. Those who spend their money in good deeds wholeheartedly and help the poor and needy people, their wealth increases surprisingly and they receive many blessing in their money.

It is mentioned in Para 3, Surah Baqarah, verse 261:

مَثَلُ الَّذِیْنَ یُنْفِقُوْنَ اَمْوَالَهُمْ فِیْ سَبِیْلِ اللّٰهِ كَمَثَلِ حَبَّةٍ اَنْۢبَتَتْ سَبْعَ سَنَابِلَ فِیْ كُلِّ سُنْۢبُلَةٍ مِّائَةُ حَبَّةٍؕ-وَ اللّٰهُ یُضٰعِفُ لِمَنْ یَّشَآءُؕ-وَ اللّٰهُ وَاسِعٌ عَلِیْمٌ(۲۶۱)

The example of those who spend their wealth on the path of Allah is similar to a grain which has sprouted seven ears (of wheat) and each ear contains a hundred grains, and Allah may increase this many a time for whomsoever He desires, and Allah is All-Encompassing, All-Knowing.

[Kanz-ul-Iman (Translation of Quran)]

In commentary to this verse, it is written in volume 1, page 295 of Tafseer Sirat-ul-Jinaan: ‘The excellence of those who give charity in the way of Allah عَزَّوَجَلَّ is being mentioned through an example that it is like a person sowing a seed (grain of wheat) in the ground which grows into 7 offshoots, and each offshoot produces 100 grains. Hence, the one sowing one seed into the ground gains 700 times more return. Similarly, the one who spends in the way of Allah عَزَّوَجَلَّ, Allah Almighty rewards him 700 times more according to his sincerity, and it is not limited to this; rather, the treasures of Allah عَزَّوَجَلَّ are full and He is Kareem [کریم] and Jawwad [جَواد]. He may grant more reward than this to whomsoever He wishes for. (Sirat-ul-Jinaan, vol. 1, pp. 395)