Answered by the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
For proof that it is permissible to save for the future, we need look no farther than the Zakâh on monetary wealth. We do not pay Zakâh on our income. We only pay Zakâh upon our savings and only if those savings have reached a certain level and have remained at or above that level for a full year.
`Âishah said: the Prophet (peace be upon him) said: “No Zakâh will be levied on money until a year passes from the time of its possession.”[Sunan Ibn Mâjah (1792) with an authentic chain of transmission as stated by al-Zayla`î in Nasb al-Râyah (2/328), al-Nawawî in al-Khulâsah, and al-Albâni in Irwâ’ al-Ghalîl (3/254)]