The Precedence of Custom in the Issue of Financial Maintenance for the Wife and Its Remedy

It is well known that financial maintenance from the husband to his wife is obligatory, but it was mentioned—O Shaykh—The Author of al-Zad: that it is not obligatory to pay for a doctor or the like. Is this correct?
According to the school of thought, medicine for the wife is not obligatory upon the husband; because it is an incidental matter outside the scope of maintenance.

And the correct view in this is that we follow custom: If it is customary for the husband to treat his wife, then it is obligatory upon him. If it is not customary to do so, it is not obligatory. I think custom differs among us. Exorbitant expenses—for example—if she needs surgery abroad, it is not obligatory for the husband. The minor expense is obligatory for the husband. And the standard you should always keep before you isAnd that is the saying of Allah, Blessed and Exalted is He: [al-Nisa:19] ,And the saying of the Messenger (peace and blessings be upon him): (And they have the right to be treated with kindness and to be given their [respective] maintenance and clothing in the accustomed manner) So follow custom in this.