He said: "My Lord! Indeed my bones have grown feeble, and grey hair has spread on my head, And I have never been unblest in my invocation to You, O my Lord!
(He said: "My Lord! Indeed my bones have grown feeble...'') meaning, "I have become weak and feeble in strength.''
(and gray hair has Ashta`al on my head,) means the gray hair has burned into the black hair. The intent is to inform of weakness and old age, and its external and internal traces.
(and I have never been unblessed in my invocation to You, O my Lord!) This means, "I have not experienced from You except that You would respond to my supplication and that You would never refuse me in whatever I ask of You.''
"And verily I fear my relatives after me, and my wife is barren. So give me from Yourself an heir."
(And verily, I fear Mawali after me,)
Mujahid, Qatadah and As-Suddi, all said, "In saying the word Mawali, he (Zakariyya) meant his succeeding relatives.''
The reason for his fear was that he was afraid that the generation that would succeed him would be a wicked generation. Thus, he asked Allah for a son who would be a Prophet after him, who would guide them with his prophethood and that which was revealed to him.
ZAKARIYYA DID NOT FEAR LEAVING BEHIND WEALTH - HE ONLY WANTED A PROPHET TO GUIDE HIS PEOPLE AFTER HIM:
He was not afraid of them inheriting his wealth. For a Prophet is too great in status, and too lofty in esteem to become remorseful over his wealth in this fashion. A Prophet would not disdain to leave his wealth to his successive relatives, and thus ask to have a son who would receive his inheritance instead of them. This is one angle of argument.
The second argument is that Allah did not mention that he (Zakariyya) was wealthy. On the contrary, he was a carpenter who ate from the earnings of his own hand. This type of person usually does not have a mass of wealth. Amassing wealth is not something normal for Prophets, for verily, they are the most abstentious in matters of this worldly life.
The third argument is that it is confirmed in the Two Sahihs, in more than one narration, that the Messenger of Allah said,
(We (the Prophets) do not leave behind inheritance (of wealth). Whatever we leave behind, then it is charity.)
In a narration recorded by At-Tirmidhi with an authentic chain of narrations, he said,
We, Prophets do not leave behind inheritance (of wealth).
Therefore, the meaning in these Hadiths restricts the meaning of Zakariyya's statement,
"Who shall inherit me, and inherit (also) the posterity of Ya'qub (Jacob) (inheritance of the religious knowledge and Prophethood, not of wealth.). And make him, my Lord, one with whom You are Well-Pleased!"
(So give me from yourself an heir. Who shall inherit me,) inheritance of prophethood.
For this reason Allah said,
"and inherit (also) the posterity of Ya`qub."
This is similar to Allah's statement,
And Sulayman inherited from Dawud.
This means that he inherited prophethood from him. If this had meant wealth, he would not have been singled with it among his other brothers. There also would have been no important benefit in mentioning it if it was referring to wealth. It is already well-known and established in all of the previous laws and divinely revealed creeds, that the son inherits the wealth of his father. Therefore, if this was not referring to a specific type of inheritance, then Allah would not have mentioned it.
All of this is supported and affirmed by what is in the authentic Hadith:
We Prophets do not leave behind any inheritance (of wealth). Whatever we leave behind, then it is charity.
Mujahid said concerning his statement (19: 6),
"His inheritance was knowledge, and Zakariyya was one of the descendants of Ya`qub."
Hushaym said, "Isma'il bin Abi Khalid informed us that Abu Salih commented about the Ayah (19: 6):
"He would be a Prophet like his forefathers were Prophets.'
(and make him, my Lord, one with whom You are well-pleased!) means "Make him pleasing to You (Allah) and your creation. Love him and make him beloved to your creatures, in both his religion and his character.''
These verses signify the quality of "hope" and "faith", a true believer has in Allah (SWT)
Although Zakariyya (AS) knew his condition, he didn't lose hope and his faith in Allah was so strong that he invokes His Lord saying that He is the One Who answers every supplicant.
These verses highlight the fact that NO invocation should be considered impossible to be answered. There is NOTHING impossible to ALLAH (SWT), and HE has the power to do or undo anything.
The story of Zakariyya (AS) has been made a part of the Qur'an to make instill hope in the believers to simply ASK from The Creator and Sustainer for things which may seem impossible.
Whatever good comes from this post is from Allah alone and any mistakes therein are mine - if found, please inform, ASAP, Insha Allah.