أَنْزَلَ مِنَ السَّمَاءِ مَاءً فَسَالَتْ أَوْدِيَةٌ بِقَدَرِهَا
Anzala minas-samā’i mā’an fasālat awdiyatun bi-qadarihā
He sends down water from the sky whereat the valleys are flooded to the extent of their capacity
(Sūrat al-Ra‘d, No.13, Āyat 17)
When Allah sends down water from the sky the land accepts and absorbs it according to its capacity. Valleys, mountains, streams, all take in water differently. The type of land also affects the amount of water it takes in. Some land absorb much of the water and from it springs lush vegetation. Other lands remain barren and nothing comes out from it. The water that comes down is the same for all, but what it brings forth depends on the capacity of the place that receives it.
Tafsīr Namūne mentions that this is an important phenomena that is also seen in the human being. Wisdom from Allah ‘azza wa-jall comes down for all but the hearts and souls receive it according to their capacity. It is as though the heart is a vessel and can only take in what fits inside. The bigger the vessel the larger the intake and hence the greater the output. Just as human beings differ in their physique, in their characters, they also differ in their capacities. Amīrul Mu’minīn Imam Ali ‘alayhis salām in a lengthy advice to his confidant Kumayl b. Ziyād al-Nakhaī says: O Kumayl, these hearts are like vessels and the best of them is the one most aware (Nahjul Balagha, Saying 147; al-Mufīd, al-Irshād, p.168).
Once when people misunderstood what Imam Ali (a) said and accused him of lying, Imam told them: By Allah it was a way of expression which you failed to appreciate and you were not capable of it. Woe to you. I am giving out these measures of expression free of any cost. I wish there were vessels good enough to hold them. ‘Certainly, you will understand it after some time’ (Q 38:88) (Nahjul Balagha, Sermon 71).
When a large internal capacity absorbs the wisdom from Allah subhānahu wa-ta‘ālā its fruits manifest through the thoughts, words, and actions that stem from it. The beauty of these are directly proportional to the depths to which the wisdom reaches in them. Some people are greatly moved when listening to the message of Almighty Allah while others remain untouched by it. A large internal capacity also means not being disturbed quickly by external stimulation. There is a calmness in the vastness of the heart that is unruffled by rocks that others might throw. A stone thrown into a pot would create a lot of ripples while the same stone would not cause any disturbance when thrown in a vast sea.
It is thus that the teachings of Islam aim to increase our internal capacity. Acquiring virtue, controlling the self, increasing in knowledge and awareness, looking after the self, etc. all expand the internal capacity. They spur growth, emotional, mental and spiritual. As a believer grows his inner capacity also grows.
Recite this verse to remind yourself that people have different inner capacities. Hence they react differently to the same thing. Your goal should be to enlarge your capacity so you are able to absorb more of the wisdom that has come down and be less affected by small things in life.
Sources: Imam Ali (a), Nahjul Balagha; Āyatullāh Nāsir Makārim Shirāzī (Ed.), Tafsīr-e Namūneh