The twins were like this, if one felt something in his head, his partner felt it.
A person who has a twin brother sometimes has feelings for the one who is jealous of his brother.
("Rabbi Yanai said, "What are these twins? If one of them is afraid of his fellow, then the Holy One, blessed be He, said, 'As the one who is with me in trouble, I will be with him in trouble.'" i.e., "What are his people, blessed be He, when they have trouble, they call upon none but the Holy One, blessed be He." - Shemot Rava (Vilna) Parashat Shemot Parasha 2)
Translation
Expression (Hebrew)
הַתְּאוֹמִים הַלָּלוּ, אִם חֲשָׁשׁ אֶחָד בְּרֹאשׁוֹ חֲבֵרוֹ מַרְגִּישׁ
Definition (Hebrew)
אָדָם שֶׁיֵּשׁ לוֹ אָח תּוֹאֵם חָשׁ לְעִתִּים תְּחוּשׁוֹת לְגַבֵּי הַמִּתְרַחֵשׁ אֵצֶל אָחִיו.
("אָמַר ר' יַנַּאי מָה הַתְּאוֹמִים הַלָּלוּ אִם חָשַׁשׁ אֶחָד בְּרֹאשׁוֹ חֲבֵרוֹ מַרְגִּישׁ כֵּן אָמַר הקב"ה כִּבְיָכוֹל (תְּהִלִּים צֵא) עִמּוֹ אָנֹכִי בְּצָרָה, ד"א מַהוּ עַמּוֹ אָנֹכִי בְּצָרָה כְּשֶׁיֵּשׁ לָהֶם צָרָה אֵינָם קוֹרְאִים אֶלָּא להקב"ה"- שְׁמוֹת רַבָּה (וִילְנָא) פָּרָשַׁת שְׁמוֹת פָּרָשָׁה ב)