Has Scriptures been tampered by the rabbis?

When you read Genesis most people in religious Christian and Jewish circles think that the word of Eloah has not been tampered in any way. Actually most Orthodox Jewish Rabbis will preach that the Torah in its present form is without any errors claiming that it is a proof of the validity of their view.

Now dear readers of all religious background I will present to your knowledge a real proof that the Torah has been tampered to fit the views of corrupted rabbis who dared to tamper with Scriptures.

Let first expose the passage in questions that we find in our present Bibles:

Genesis 17:  ¹ When Abram was ninety-nine years old, YHWH appeared to Abram and said to him, “I am EL Almighty ; walk before Me and be blameless. ² And I will make My covenant between Me and you, and will multiply you exceedingly.”...
 ^...
 24 Abraham was ninety-nine years old when he was circumcised in the flesh of his foreskin. ²⁵ And Ishmael his son was thirteen years old when he was circumcised in the flesh of his foreskin. 

Note that Ishmael was 13 years old and Abraham 99 when they were circumcised. 

Now let us go to Genesis 21

Genesis 21:  ⁴ Then Abraham circumcised his son Isaac when he was eight days old, as Elohim had commanded him. ⁵ Now Abraham was one hundred years old when his son Isaac was born to him.

Note that Abraham is now 100 years old and Isaac 8 days and Ishmael 13+1=14 years old. 

Now follow the tampering and how Rabbis dared to change Scriptures to put aside Ishmael:

14 And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child, and sent her away: and she departed, and wandered in the wilderness of Beer-sheba. 14 And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child, and sent her away: and she departed, and wandered in the wilderness of Beer-sheba.
 ¹⁴ And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child, and sent her away: and she departed, and wandered in the wilderness of Beersheba. (Genesis 21)

How can a more than 14 years old boy be put on the shoulder of a woman? 

Verse 15 confirms that Ishmael who was normally more than 14 years old became a mere baby in Genesis 21:

¹⁵ And the water was spent in the bottle, and she cast the child under one of the shrubs. 

You can not cast a young adult under shrubs nor bear him on your back. Only a young child or baby can be held in this matter.

This major discrepancy cast doubt on the writings of the Torah and the whole Jewish Bible:

Therefore I hope for the benefit of all that actual honest rabbis will tackle this problem and explain this major discrepancy. 

P.S: Here the text of Genesis 21 v.14 which is even clearer to the fact that Ishmael is presented as the child being put on the shoulder of his mother:

וַיַּשְׁכֵּם אַבְרָהָם בַּבֹּקֶר וַיִּקַּח־לֶחֶם וְחֵמַת מַיִם וַיִּתֵּן אֶל־הָגָר שָׂם עַל־שִׁכְמָהּ וְאֶת־הַיֶּלֶד וַיְשַׁלְּחֶהָ וַתֵּלֶךְ וַתֵּתַע בְּמִדְבַּר בְּאֵר שָׁבַע׃


  14 And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child, and sent her away: and she departed, and wandered in the wilderness of Beer-sheba.