Tirmidhi

Explanation:
1:
There can be several reasons for this:

(1)
Drinking water directly from the mouth of a waterskin (mashkiza) can alter the taste of the water.

(2)
There is a risk that there might be some poisonous insect or creature inside it.

(3)
If the mouth of the waterskin is wide and large, then when drinking from its mouth, the person drinking cannot avoid the splashes of falling water, and an excessive amount of water may enter his throat, which carries the danger of choking, and this can be harmful.

(4) One opinion is that this prohibition pertains to waterskins with large and wide mouths.

(5) Some people say that the narration granting concession abrogates this.

(6) In case of necessity, it is permissible.

Hadith Commentary:
And Al-Khattabi has asserted that the explanation of "ikhtinath" is from the words of Az-Zuhri.
That is, according to Al-Khattabi, the interpretation of the word "ikhtinath" is the statement of Az-Zuhri.
In Musnad Abu Bakr ibn Abi Shaybah, it is mentioned that a person drank water by putting his mouth to a water-skin, and a small snake from the water-skin entered his stomach; for this reason, the Prophet (sallallahu alayhi wa sallam) strictly forbade this action.
Those narrations from which permissibility is established have been abrogated by this incident.
(Fath al-Bari)
This explanation is related to the previous hadith.

Hadith Commentary:
(19 Drinking water directly from the mouth of a waterskin or by putting one’s mouth to a spout is a disliked act.
It is possible that the waterskin may be damaged, and in addition, it is also possible that some harmful thing may have entered it without the drinker’s knowledge, causing harm. Accordingly, it is mentioned in the hadith that during the blessed era of the Messenger of Allah (sallallahu alayhi wa sallam), a person violated this instruction and, at night, turned the mouth of the waterskin upside down, from which a snake emerged.
(Sunan Ibn Majah, Al-Ashribah, Hadith: 3419) (2)
A person should, as much as possible, act upon the instructions of the Messenger of Allah (sallallahu alayhi wa sallam); otherwise, there is a risk of harm.

Hadith Footnote:
Vocabulary of the Hadith:
Ikhtinath:
To turn away the mouth or to bend its tip.

Benefits and Issues:
Benefit.
In the next hadith (3721), there is a statement regarding its permissibility.
However, that narration is weak in its chain of transmission.
Therefore, the prohibition is given preference.
Nevertheless, this prohibition is of a discouraging (tanzihi) nature.
As has been clarified earlier in the benefits of hadith (3719).

Benefits and Issues:
➊
Regarding the words in parentheses in the hadith, the author of Bazl al-Majhud has mentioned in the footnote that these are present in some manuscripts of Sunan Abu Dawood.
We have written them for the benefit of the general public.

➋
The broken part of a cup or plate is generally not properly clean, so it is possible that this area may injure the lips.
Or, while drinking, the beverage may spill outside the lips, which is not appropriate in any way.
Similarly, blowing into water, tea, milk, or other food is not permissible in any way.
However, there is a difference of opinion regarding blowing for the purpose of ruqyah (spiritual healing).
Some scholars, under the general principle, also consider this impermissible.
Whereas some scholars hold the view that reciting Surah al-Fatihah and prescribed supplications (masnun du‘a) in ruqyah creates a certain effect in it.
Therefore, it is permissible to blow after reciting for ruqyah.
(For detailed evidences, see:
Weekly Al-I‘tisam, Lahore, 1st August 2003,
Vol. 555, Issue 3.) It should be noted that when the scholars describe such prohibitions in these types of hadith as “nahy tanzihi” or “makruh tanzihi” (discouraged but not strictly forbidden), the meaning is that if it happens occasionally, the one who does so should not be considered a major sinner.
Nevertheless, the command of the Messenger of Allah (sallallahu alayhi wa sallam) is always obligatory to follow.
If someone considers it meaningless or deliberately opposes it out of contempt, then this is disbelief (kufr).